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Modbus Program for Alicat CODA Flow Controller

Hello -- I'm very new to LabVIEW, and I'm trying to write a program that can communicate with an Alicat CODA Flow controller (manual attached - page 11 gives Modbus details).

 

I started with a really simple program to see if I can communicate with the controller, and I tried to write mass flow units to lb/min. 

 

When I run the program, I get the error pictured below. I'm sure I'm missing several items to make this program work -- but is there anything I can do to successfully read and write to the controller? I attached the VI -- we use LabVIEW 2020.

 

Thank you in advance.

 

sparg008_0-1686933406021.png

sparg008_1-1686933448603.png

sparg008_2-1686933464363.png

 

 

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Message 1 of 3
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Without your device it's awfully hard to troubleshoot your code.

 

But you could use the Trace function to determine if the error is coming from the register read or register write.

 

That and the manual should point you in the right direction 

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=== Engineer Ambiguously ===
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Message 2 of 3
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Hi,

 

According to the manual you should use FC 16 (write multiple registers) to write to a register.

Function code 6 is force single register.

 

Kees

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